Newbie Question

*To*: mathgroup at smc.vnet.net*Subject*: [mg32686] Newbie Question*From*: "Brunsman, Kenneth J" <kbrunsman at ou.edu>*Date*: Wed, 6 Feb 2002 03:41:43 -0500 (EST)*Sender*: owner-wri-mathgroup at wolfram.com

Hello Group, I can't believe that I am asking this question, but ... I'm tired of Fortran and find the symbolic part of Mathematica extremely useful. I have a list with Dimensions = {10,000, 6} and I need to find the Percent Difference between items in a column. I can parse out the column I need using Take [data [[All, Column #]]] --- no big deal. So far, so good. Now here's the problem --- How do I get % Differences between any of 10,000 items in that list? I need to take % Differences between adjacent pairs, i.e. n and n-1, as well as items n and n-m where m can range from 1 to 10,000. Further, I need to make sure that this code runs fast because I'm about to run this on a data set of 10^8 data points (financial times series). I could do this standing on my head in Fortran, but I'm bound and determined to learn Mathematica if it takes the rest of my unnatural life. This is my first time attempting list processing and all I'm doing is screwing up royally. Help is greatly appreciated. Thanks in advance, Best to all, Ken Brunsman University of Oklahoma Michael F. Price College of Business Division of Management 307 W. Brooks, Room 205 Norman, OK 73019-4006 405.325-5689

**Follow-Ups**:**Re: Newbie Question***From:*Tomas Garza <tgarza01@prodigy.net.mx>

**Re: Newbie Question***From:*Sseziwa Mukasa <mukasa@jeol.com>